LS Engine Swap In A Muscle Car - How It Works

LS swaps are smoking hot and here’s how to fit one inside your muscle car

Computers

Liz Miles: The Holley Dominator EFI system was built with the LS-series engine in mind. It uses all of the same inputs and outputs as a factory LS engine so it can easily be adapted to our EFI system. The software allows for nearly infinite adjustment in an extremely user-friendly format. It controls the LS engine’s injectors, ignition, and electronic automatic transmission. It can also read and tune GM’s drive-by-wire throttle body for exact control. Holley’s tuning software allows you to be as specific as you like while giving you set-it-and-forget-it ease with its self-learning programming. We carry LS engine wiring harnesses, perfect for a swap vehicle where you’re starting from scratch. If you don’t need drive-by-wire or transmission control, we also offer our HP EFI units with LS harnesses.

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Trans Tunnel Clearance

Mark Campbell: Late-model transmissions like the Tremec T56 and GM 4L60E will fit most Chevy muscle cars without a problem. Rumor has it that you have to cut up the trans tunnel, but that simply isn’t true. For instance, trans tunnel clearance is very tight on a Chevelle, but you can still fit a T56 without any cutting. The reverse lockout solenoid is what usually causes clearance problems in these cars. When it comes to fitting a trans inside the tunnel, you just have to use the right motor mounts and the correct driveshaft angle to get everything positioned properly.

Swap Bundles

Marc Lewis: All of Hedman’s Muscle Rods headers are built in conjunction with vehicle- and transmission-specific motor mounts and transmission crossmembers. When choosing these mounts for use with LS swap headers, it is important to choose the conversion kit that is specific not only to your vehicle, but the transmission you plan on using as well. Regardless of the application, our R&D team made sure that all mounts and headers allow the engine and transmission to be set with the recommended 3- to 5-degree pinion angle. In addition to the headers themselves, Hedman’s LS conversion kits come complete with a full set of engine mounts that are manufactured using 1/4-inch cold-rolled steel plate, polyurethane bushings, and Grade 8–hardened mounting hardware. Also included is a complete transmission crossmember that features thick-wall construction, a polyurethane transmission mount, and hardened Grade 8 hardware. To protect the components from the elements, and to make them look sharp, all mounts and crossmember components are given a hearty, silver powdercoated finish. Muscle Rods LS Conversion kits are very application specific. For example, four conversion kits are available for ’68-72 A-bodies, depending on whether your vehicle is a coupe or convertible, and whether you are using a manual or automatic transmission.

Clutch and Shifter

Mark Campbell: With most LS swaps where a T56 transmission is used, the shifter location is right where you want it. Street and Performance offers relocation kits that can move the shifter 2 to 4 inches forward. However, the only instances where they are necessary are when you’re trying to get the shifter to line up into a factory center console. Without a console, you rarely have to move the shifter. As for the clutch linkage, for the sake of simplicity we recommend using the stock hydraulics and pedal assembly. That way, it’s a completely bolt-in affair, and all you have to do is hook up the hydraulics to the stock pedal in the new car.